Is 55 too old to become literate, or too old to learn about numbers? I believe you're probably never too old to pick up programming. I think programming is just one step beyond literacy and numeracy on the same continuum, but very similar to both of those. Programming is like learning to use words and numbers together.
Also, you may not realize at first that not all programming is “computer programming”, so you may find that as you learn “computer programming” you will realize the ways in which you have been thinking programatically, and programming for years already without computers!
If you need any encouragement, I'm just a young guy (29) but I'm focusing on learning programming after I already had a career in graphic design, partly just for personal growth and expansion. Living in the small fraction of human history where computers exist and are cheap and available is an amazing gift!